Open AccessCombining Chemical Knowledge and Quantum Calculation for Interpreting Low-Energy Product Ion Spectra of Metabolite Adduct Ions: Sodiated Diterpene Diester Species as a Case Study
Author(s) -
JeanClaude Tabet,
Yves Gimbert,
Annelaure Damont,
David Touboul,
François Fenaille,
Amina S. Woods
Publication year - 2021
Publication title -
journal of the american society for mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.961
H-Index - 127
eISSN - 1879-1123
pISSN - 1044-0305
DOI - 10.1021/jasms.1c00154
Subject(s) - chemistry , protonation , adduct , electrospray ionization , mass spectrum , ion , tandem mass spectrometry , mass spectrometry , molecule , metabolite , diterpene , electrospray , computational chemistry , analytical chemistry (journal) , organic chemistry , chromatography , biochemistry
We investigated the product ion spectra of [M + Na] + from diterpene diester species and low molecular mass metabolites analyzed by electrospray ionization (ESI). Mainly, the formation of protonated salt structures was proposed to explain the observed neutral losses of carboxylic acids. It also facilitates understanding sodium retention on product ions or on neutral losses. In addition, the occurrence of consecutive carboxylic acid losses is rather unexpected under resonant excitation conditions. Quantum calculation demonstrated that the exothermic character of such neutral losses can represent a relevant explanation. There is no doubt that the formation and role of the protonated salt structures will be helpful for a better understanding and software-assisted interpretation of tandem mass spectra from small molecules, especially in the ever-growing metabolomics field.